We have already demonstrated that lytic lipids are present in greater concentrations in stress-ulcerated rat gastric mucosa than in normal controls. Preliminary evidence for the existence of phospholipase A1 and A2 was obtained in our laboratory. These enzymes are probably responsible for the lytic lipids generated in the mucosa. The localization, optimum pH and kinetic aspects of the gastric phospholipases will be studied. The effects of bile salts, Ca 2 ion, glycoproteins and physiological state on the level of enzyme activity also will be ascertained. The fate of the liberated lysophosphatides and fatty acids will be studied, too, since the further degradation of lysophosphatides or their reacylation may protect the mucosa. BIBLIOGRAPHIC REFERENCES: Slomiany, A., Slomiany, B. L. and Horowitz, M. I. Blood Group A Active Glycolipid Variants from Hog Gastric Mucosa. In Glycolipid Methodology, ed. L. A. Witting, p. 49-75 (1976). Amer. Oil Chemists Soc., Champaign, Ill. Slomiany, B. L., Slomiany, A. and Horowitz, M. I. Isolation and Characterization of Branched Fucolipids from Hog Gastric Mucosa. Fed. Proc. 35, Abst. 1443 (1976).